The present invention relates to an ultrasonic imaging apparatus which can output Doppler data and M-mode data and/or ECG (Electrocardiograph) and PCG (Phonocardiograph) data together.
An ultrasonic imaging apparatus is widely used particularly in the medical field as an ultrasonic diagnosis apparatus. The ultrasonic diagnosis apparatus has a function of not only displaying a tomographic image, but also displaying ECG and PCG data together with Doppler data to represent blood flow characteristics on a single screen.
When the ECG, PCG, and M-mode image are displayed together with Doppler data pattern, a time from when a valve of the heart is opened until the blood flow starts, i.e., PEP (Pre Ejection Period) can be measured. The cardiac function can be diagnosed in accordance with this measurement value.
However, in order to obtain Doppler data, echo signals obtained from an ultrasonic transducer are subjected to FFT (Fast Fourier Transformation) for frequency analysis.
When the Doppler data is to be obtained by the FFT, the echo signal must be subjected to sampling and arithmetic operations. Therefore, a considerable time is required from when the echo signal is output until the Doppler signal is output. For this reason, the Doppler data output is to be delayed from the M-mode data and the ECG and PCG data. This delay time is included in the PEP, and hence the PEP cannot be accurately measured.